1. Field of the Invention
The present invention relates to a method and means for durably preserving graphical data transferred onto a transparent material.
2. Discussion of the Background Art
Equipment has appeared recently that lies within the meaning of the term “compact disc” and on which data is inscribed using a process that is binary and known to the person skilled in the art as characterizing the basic concept of computer science.
The physical expression is constituted by a succession of depressions and of projections, represented by 1s and 0s in computer language, or commonly by the terms “on” and “off”.
All such known devices as briefly described above suffer from the same prohibitive phenomenon when attempting to satisfy a requirement for extreme durability, namely they are made of materials of the polymer type or having similar characteristics, such materials being of low hardness, and easily pressable, where pressing is the very basis of the process used to obtain them, i.e. to duplicate them, as implemented in mass production on the basis of a master made of metal or of hard materials.
Devices are known on which information is embodied by a succession of depressions or projections or studs, or by a succession of lines, e.g.: bar codes, that are interpreted and read by means of a coherent light beam, such as a light beam formed by a laser.
All devices for carrying information contained in this way require frequent refreshing after a variable length of time, which length of time is measured in centuries in the context of the present invention, and they can even require new copies to be made.
Another known method that is proposed by its inventors as satisfying the dual objective of miniaturization and of data preservation is described by the Los Alamos National Laboratory (New Mexico 87545) Analysis of the claims attached to that description reveals firstly a high cost given the materials used, and secondly relative sensitivity to various attacks, in particular of physico-chemical origin as stated by the inventors of the method in question.